1. Field of the Invention
The present invention relates generally to telemetering systems, and more specifically to a wireless telemetering system in which observation data from remote sensor nodes are wirelessly collected at a central location at periodic intervals for power saving purposes.
2. Description of the Related Art
A known telemetering system comprises a plurality of wireless modules to perform measurement of physical quantities at remote locations. For power saving purposes, each sensor module is provided with a time-keeping device and the current time supplied from the device is constantly compared to power saving time-schedule. When the current time of day coincides with each successive instant of the time schedule, the sensor module is activated briefly and transmits a signal indicating a quantity being measured. Since the prior art sensor modules were designed to meet strict specifications that they must be of small design for less power consumption and be as less complex as possible for unattended operation, the power saving time schedule were manually set in each of the sensor modules at the time the system is initially started. Once the telemetering system became operational, it was impossible to update the time schedule of the remote sensor modules.
However, there is a need to control the power saving time schedule of each remote sensor module from a central location in a flexible manner. Further, there exists a need for controlling the sensor module to alter its process of measurement from the central location.